Minimally invasive interventions on patients are carried out particularly for the purposes of diagnosis or smaller operations in the body of a patient. Certain objects, for instance catheters or guide wires, are hereby inserted into the body of the patient. To this end, an x-ray image recording system is hereby frequently used to track the specific objects, i.e. to image the specific objects in the patient environment.
One problem in the prior art is the optimization of the x-ray image recording parameters. The number of adjustable parameters increases as the functionality of x-ray image recording systems increases. It was hitherto left to the user to adjust these parameters as well as possible. This is however not always done perfectly, since the user is concentrating on the actual intervention and diagnosis. Facilities with plenty of human resources occasionally have additional personnel who attend exclusively to the adjustment of the x-ray image parameters.
WO 03/059166 A2 discloses the use of an image data processing device in conjunction with the recording of x-ray images. The imaging of body prostheses in x-ray images in particular is mentioned as the field of application. A reference image is recorded, in which the parameters of the x-ray image recording system are set as optimally as possible. This above all concerns the position of the structure to be imaged in the x-ray image. If an image is recorded at a later time, the contours of the imaged structure are automatically evaluated and it is indicated to a user via a monitor how he/she has to change the parameters of the x-ray image recording system in order to reproduce the situation of the reference image recorded at the start. With one embodiment activation can be carried out automatically. Aside from controlling the position of the imaged structure in the x-ray image, further parameters can also be considered, for instance the voltage present at the x-ray light generator and current passed through. The parameters can also be adjusted as a function of the gray-scale values in an image. To this end, in WO 03/059166 A2, a calibration phantom is introduced into the image region in addition to the imaged object.